1. Field of the Invention
This invention relates generally to the field of chemical reactions. More specifically, the invention relates to methods of making chlorohydrins incorporating high shear mixing.
2. Background of the Invention
Chlorohydrins are useful as intermediates in producing various compounds. For example, propylene chlorohydrin and butylene chlorohydrin are used in producing propylene oxide and butylene oxide, respectively.
Various processes are known for the production of chlorohydrins. For example, olefin chlorohydrins are typically prepared by reacting an olefin with chlorine in the presence of water. This process is believed to occur by means of an intermediate cyclic chloronium ion which reacts with the water to form an olefin chlorohydrin. The olefin may be one containing from 8 to about 30 carbon atoms. However, the process also concurrently forms undesirable dichloride byproducts when aqueous chloride ions react with the cyclic chloronium ions. Significant yield losses are typically suffered and the byproducts must be separated from the desired olefin chlorohydrin, an operation that adds to the cost of making the chlorohydrin. Alternatively, the process described above may include a water immiscible solvent. Therefore, the reaction would entail the addition of hypochlorous acid to a long chain olefin in the presence of water in a water immiscible solvent. Suitable solvents include decane, chloroform and petroleum ether.
Other processes for producing chlorohydrins involve reacting olefins with hypochlorous acid, wherein the process requires preliminarily acidifying the olefin with gaseous hydrochloric acid and carrying out the process at a pH of between 2 to 7, and preferably between 5 to 6. Another method of making chlorohydrins involves preparing hypochlorous acid by reacting chlorine and water in the presence of alkaline earth metal hydroxides (maintaining a pH below 7.0), then, reacting the hypochlorous acid mixture with a vinyl group-containing compound. Alternatively the preparation of chlorohydrin may be achieved by reaction of olephins with trichloroisocyanuric acid in alcohols, acetic acid or aqueous acetone.
Various other methods of forming chlorohydrins are also well known such as reacting olefins with t-butyl hypochlorite or hypochlorous acid substantially free of chloride ions. However, these methods typically either result in the production of numerous byproducts or require various, costly processing steps or long reaction times, thus hindering the commercial viability of the methods. For these reasons, there remains a need for a process for producing chlorohydrin that is effective and results in high yields of the desired product.
In light of the above, it is apparent that research has been focused on different reaction pathways in producing chlorohydrins. However, none of these methods discuss improving the solubility and mass transfer of the reactants through improved mixing.
Consequently, there is a need for accelerated methods for making chlorohydrins by improving the mixing of olefins into the liquid chlorinating phase.